Polysaccharide fibers and method for producing same

Abstract

The present invention relates to a method for the production of polysaccharide fibers which contain (1.fwdarw.3)-glucan as a fiber-forming substance, as well as to the fibers made thereby, and to their use.

Claims

1. A method of producing a polysaccharide fiber whose fiber-forming substance is (1.fwdarw.3)-glucan, wherein the method comprises: (i) preparing a spinning solution comprising (1.fwdarw.3)-glucan, sodium hydroxide, and carbon disulfide (CS.sub.2), wherein there is about 5% to about 7.5% by weight CS.sub.2 relative to the (1.fwdarw.3)-glucan, and (ii) extruding the spinning solution to produce the polysaccharide fibers.

2. The method according to claim 1, wherein at least 90% of the (1.fwdarw.3)-glucan are hexose units and at least 50% of the hexose units are linked via (1.fwdarw.3)-glycosidic bonds.

3. The method according to claim 1, wherein the fiber is a staple fiber or a continuous filament.

4. The method according to claim 1, wherein step (i) comprises first preparing a solution comprising the (1.fwdarw.3)-glucan and the sodium hydroxide, and then admixing the CS.sub.2 to prepare the spinning solution.

5. The method according to claim 1, further comprising (iii) stretching the polysaccharide fiber.

6. The method according to claim 1, wherein the weight-average degree of polymerization (DPw) of the (1.fwdarw.3)-glucan is between 200 and 2000.

7. The method according to claim 6, wherein the DPw of the (1.fwdarw.3)-glucan is between 500 and 1000.

Description

EXAMPLES

(1) The degree of polymerization of the (1.fwdarw.3)-glucans was determined by means of GPC in DMAc/LiCl. Subsequently, it is always the weight average of the degree of polymerization (DP.sub.w) that is specified.

Example 1

(2) An aqueous glucan solution containing 9.1% of (1.fwdarw.3)-glucan with a DP.sub.W of 800 as well as 4.5% by weight of NaOH was reacted with 7.5% of CS.sub.2 (percent by weight calculated relative to the fiber-forming material). The viscose obtained in this way contained 9% by weight of fiber-forming material, 4.5% by weight of NaOH, and 0.57% by weight of sulfur. By using a spinneret, the solution was extruded into a regeneration bath containing 100 g/l of sulfuric acid, 330 g/l of sodium sulfate, and 35 g/l of zinc sulfate. The spinneret had 1053 perforations with a diameter of 50 m. 2.5% by weight of a nitrogen-containing auxiliary agent (Leomin AC80) were added to the viscose spinning solution. In order to achieve adequate fiber strength, stretching by approx. 75% was carried out in the second bath (92 C., 15 g/l of H.sub.2SO.sub.4). The draw-off velocity was 30 m/min.

(3) The properties of the obtained fibers are listed in Table 1.

Example 2

(4) An aqueous glucan solution containing 11% of (1.fwdarw.3)-glucan with a DP.sub.W of 1000 as well as 4.8% by weight of NaOH was reacted with 15% of CS.sub.2 (percent by weight calculated relative to the fiber-forming material). The viscose obtained in this way contained 10.8% by weight of fiber-forming material, 4.7% by weight of NaOH, and 1.37% by weight of sulfur. By using a spinneret, the solution was extruded into a regeneration bath containing 100 g/l of sulfuric acid, 330 g/l of sodium sulfate, and 45 g/l of zinc sulfate. The spinneret had 1053 perforations with a diameter of 50 m. 3% by weight of a nitrogen-containing auxiliary agent were added to the viscose spinning solution. In order to achieve adequate fiber strength, stretching by approx. 75% was carried out in the second bath (92 C., 15 g/l of H.sub.2SO.sub.4). The draw-off velocity was 25 m/min. The properties of the obtained fibers are listed in Table 1.

Example 3

(5) An aqueous glucan solution containing 12.5% of (1.fwdarw.3)-glucan with a DP.sub.W of 800 as well as 4.4% by weight of NaOH was reacted with 12% of CS.sub.2 (percent by weight calculated relative to the fiber-forming material). The viscose obtained in this way contained 12.3% by weight of fiber-forming material, 4.3% by weight of NaOH, and 1.24% by weight of sulfur. By using a spinneret, the solution was extruded into a regeneration bath containing 90 g/l of sulfuric acid, 330 g/l of sodium sulfate, and 45 g/l of zinc sulfate. The spinneret had 1053 perforations with a diameter of 50 m. 1% by weight of a nitrogen-containing auxiliary agent was added to the viscose spinning solution. In order to achieve adequate fiber strength, stretching by approx. 75% was carried out in the second bath (92 C., 15 g/l of H.sub.2SO.sub.4). The draw-off velocity was 27 m/min. The properties of the obtained fibers are listed in Table 1.

(6) TABLE-US-00001 TABLE 1 titer FFk FDk example dtex cN/tex % ex. 1 1.7 17.3 19.1 ex. 2 1.3 23.4 16.3 ex. 3 1.5 21.8 18.1 FFk fiber strength, conditioned FDk fiber elongation, conditioned